


tumbling down, tumbling down (we are not falling)

by Anonymous



Series: KnY x FGO dump [1]
Category: Fate/Grand Order, 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Kimetsu no Yaiba (Manga)
Genre: Alternate Universe - Canon Divergence, Fujimaru Ritsuka as Kamado Tanjirou, Gen, I dont even know what im writing help, I mean, M/M, Rengoku Lives, Spoiler Alert for those who dont read manga, nezuko pov, no beta we die like men, pure self indulgent, reversal au
Language: English
Status: Completed
Published: 2019-10-31
Updated: 2019-10-31
Packaged: 2021-01-15 13:23:13
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 6,303
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21254057
Author URL: https://archiveofourown.org/
Summary: Sometimes, Nezuko felt like she didn't know Tanjirou at all. But it didn't mean he had stopped become her Big Brother.She just needed to observe more and stood beside him, always..Or: the adventure of Kamado Tanjirou gathered his previous life's scattered memories as Fujimaru Ritsuka and once again fought for humanity, in the eyes of Kamado Nezuko.





	tumbling down, tumbling down (we are not falling)

**Author's Note:**

> i  
i actually made this approximately four days straight wha t

Kamado Tanjirou was a peculiar demon.

First, he didn't eat human. It's officially confirmed as he had repeatedly ignored the smell of fresh blood and chose to consume human food as substitution.

It's highly noted that he could suppress, if he hadn't eradicated his demon's cannibalism instinct. How he chose to tend Shinazugawa Sanemi's wound and didn't show any indication of being tempted was the concrete proof. After all, the Wind Pillar's blood is famous for its rarity.

Second, he was, surprisingly, very intelligent for someone who came from poor family. Nezuko once said that it's Tanjirou who had taught her and her siblings how to read and write, and a small portion of foreign language. And thus, even though they didn't get any formal education, Nezuko was pretty confident with her intellectual.

At very least, she was a little bit above Zenitsu. While it sounded not impressive, it actually is as Zenitsu actually got a formal education and much older than Nezuko.

It's still a mystery where Tanjirou got all of his vast knowledge. According to Nezuko who was more than ready to brag her brother, Tanjirou sometimes would borrow scrolls and books from other neighbors. He might learn from that, but again, no one could be sure about that.

On other side, Inosuke finally could brag to his teammates as he finally able to write and read.

How Tanjirou could teach him how to read when the demon couldn't say anything other than hum and grunts is a mystery far greater than previous.

Third and foremost, his eyes were far too kind yet saddened to see.

There's nothing nice about Demon's eyes. Their eyes are always full of hate, blood lust, and evil that nobody would hold any pity as they chopped their neck. It's not unlike killing a bug.

But--Tanjirou was different. Although his eyes now slited, a proof that he is now no longer a human, the endless warmth and kindness never leave from those pair of rubies. He had such kind eyes that was too humane and it made anyone who gazed upon them left brokenhearted.

It reminded them that he was a victim. He was a good person that you could only met once in lifetime that didn't deserve this kind of misdeed yet he did because life is unfair and he's a victim and he didn't deserve this and--

Zenitsu once again broke into tears.

And fourth, something that didn't have to be mentioned, was he, Kamado Tanjirou, will never ever attack human.

One said it's because it was something Urokodaki Sakonji had implemented.

One said it's simply his nature.

One said it's because that was a common sense.

But, if one asked the person himself, his answer is:

"Humanity... Must be preserved. It's my job to protect them."

And, no,

Tanjirou didn't even knew why he had to.

He simply knew.

* * *

It's easy to forget the fact that Kamado Tanjirou is not a human anymore.

Put his inability to use verbal speech and inhuman features aside, he more or less acted like normal human.

He could eat human food, he didn't 24/7 reek blood lust, he loved to make food for others, he liked to play with children at Butterfly estate, and he could walk under open sun.

Albeit he would be slightly sluggish if he was under sun far too long without his trusty umbrella.

It couldn't be say it's weird, though. Many people were like that too.

Kamado Tanjirou was truly far humane than normal people.

* * *

"Ca...ru. Caru... de... A."

"Oi, Nekozubo, what's your brother doing?"

"My name is Nezuko..." The black haired girl sighed in defeat. It's no use to correct Inosuke; the man was too hardheaded.

She looked at her brother who stared at the open sky, kept murmuring the same word over and over--as if he was practicing to say the word correctly.

"I don't know," she admitted. "He has been doing it since yesterday, but he refuse to tell me what's the word. I guess it's just a personal thing, or nothing important."

Inosuke made a humming noise. "It's kinda weird though."

"Well--"

"_Karudea__!_"

They jolted in surprise as Tanjirou cheerily shouted the word.

"Big Brother? What's wrong?"

"_Karudea__, __karudea__!_" He repeated with a big smile. There were thousand stars shone in his eyes. "_Ma-chu! __Ro__-ma-n__! __Bi-n-__ci__-chan__!_"

"Haa? What does it mean, Gonpachiro? Are you mocking me?!"

Even until today, Tanjirou kept his mouth shut about it. He kept saying it though, as if he would forget that word when he stopped.

* * *

It could be said Tanjirou was a walking lucky charm.

Just by his presence, it felt like anything impossible could become possible. Any helpless situation, as long as they never lost hope, could be turned.

It had happened many times Nezuko had lost count.

His brothers' survival. Two years under Urokodaki. The last trial and meeting Makomo and Sabito. Demon hand's death. Their first task. Their next task, and then--their first Twelve Moon Demon.

Nezuko couldn't help but shuddered reminiscing it. If his brother weren't there, she didn't know what would happen.

She barely remembered what had happened back then. One one moment she was on march with broken sword and Fire God Breath Technique she barely mastered on her tow, and next she was already engulfed within Tanjirou's embrace.

It might has something to do with Tanjirou's Demon Art. Because the atmosphere had changed into something... different.

(_It felt like deep, dark prison. It felt like burning sun and shining white. It felt like solid wall it felt like endless stars it felt __like--_

_Unnatural._

_Home.)_

She didn't have a heart to ask his brother about that. It's not because his brother's inability to speak coherently or because he's suck at explaining.

It's because... There's sadness lingered on him since then. It's weak, but it was there.

Nezuko didn't want to make him saddened more than this. And so she threw away her curiosity to the deepest part of brain, put more focus on her current goal and present.

She vowed to accept his brother no matter what, like how his brother saw and accepted people they had met wholly. She convinced herself that his lingered sadness and what had happened back in the forest was just coincidence, was something she shouldn't be worried about.

...until the train incident happened.

Two demon. Two Twelve Moon demon, one Lower Moon and one Upper Moon. One demon capable to trap everyone inside their dream, and one demon had an immense strength to inhumane point.

She genuinely thought it was all hopeless. The Lower Moon somewhat had been taken care of, but the Third Upper Moon was on entire different level. They barely stood on their ground, lest attacked back.

Nezuko briefly noted that his brother had been missing since they had fallen asleep. There's a curious rope tied up their arm but she quickly brushed it off.

(After awhile, she finally had such good dream... Too bad she was still in the middle of work.)

And then, just when the demon's fist had balled up and half-way from impaling Rengoku's chest, Tanjirou appeared and kicked him several meters away--giving them a chance to take a breath.

Nezuko almost wept in joy at the sight of her brother; at very least they could hold off until the sun came out. Tanjirou, although he hadn't waken up his Demon Art, powerful enough to go on tow with the Third Upper Moon.

"Onii--" Nezuko paused as she took a good look on Tanjirou's face.

It was a face void of emotion. There was no anger, sadness, or even the usual undying determination. His burgundy eyes that held warmth and love were darkened and there's no light--like an endless abyss.

It's as if the man in front of her was no longer Tanjirou, rather moving doll void of emotion that had her brother's appearence.

_...No. It's still Big Brother. Calm, Nezuko_.

Nezuko forced herself to let our her breath. He was still her brother. He had no external injury, but it seemed that something had happened before he came here.

She didn't dare to bother him afterward, even when the day had arrived and they were evacuated to Butterfly Estate. Rengoku, who suffered most injuries, barely escaped death and had to forfeit from his pillar position.

(Not that he complained, though. He was still surprised he's actually survived.

_Umu,_ the man nodded to himself. _I should thank Kamado boy for saving my life! And introduce him to __Senjurou__ later. They'll be a good friend, I'm sure!_)

Nezuko knew something had bothered Tanjirou greatly, and so she let him to sort out his thoughts until he could bounce back to his normal self.

God, Nezuko couldn't stand it at all seeing how downhearted her dearly brother was. She wanted to hug him tight and pat him and let him saw her dream he had back in train so _please wipe off that frown, I hate seeing you so sad it feels terrible I don't like it _**_I don't like it at all._**

It took couple days with a big dose of hugs and headpats to make Tanjirou went back to his old self.

Since that day, Nezuko vowed to herself to become stronger than ever so she could protect Tanjirou's happiness.

* * *

Nezuko knew Tanjirou had some effect on people, but she didn't... expect it would become like this.

Yes, she knew her brother is attractive by appearance and personality. He was their hometown's most prided beau. Not that he knew it but, details.

Yes, she knew her brother had many admirers. She often overheard several kakushi merrily talking about Tanjirou, mostly about how adorable he was when shrinking his body on the same size with toddler and how polite he was. But, again, _details_.

What's important now is the current situation that laid in front of her eyes. Tanjirou's fate it's now up to her. She must think about this carefully or another war would break down. No, no, this Estate already suffered enough. She didn't want to cause Shinobu another problem.

But, first...

"Um, Uzui-san, Rengoku-san, Muichirou-kun, Shinazugawa-san, and Giyuu-san... Can you please let go my brother? It looks uncomfortable..."

* * *

"Do you believe in reincarnation, Kamado Nezuko?"

Nezuko paused at the question Ubuyashiki had thrown to her. The said man only smiled serenely, waiting for her answer patiently.

"I do," she said. "At very least, I want to believe it."

She always pray for every demon she had slew to be reincarnated as a better person in next life. Although she had some doubt, it wouldn't hurt to play make-believe.

"Then, what do you think your previous life how like?"

"Eh?" She startled by the sudden hard question. "Un.... Mmmm... My previous life, uh..."

The sickly man chuckled softly. "You don't have to answer it, Kamado-san, it's a rhetoric question," he said to reassure. Nezuko blushed and nodded, inviting another chuckle.

"It's about your brother, Kamado Tanjirou-san."

"Big Brother?"

"Yes," he said. His eyes were empty, but Nezuko felt like as if he was staring to the very core of her soul.

"I think your brother may be one of those gentle spirits that had entered circle of reincarnation, and still keeping shards of memories from his previous life," he said, serene smile never escaped his face. Nezuko gasped in surprise. "But he doesn't realize it yet. Maybe he will, sooner or later, or maybe he won't ever remember it."

Nezuko didn't say anything, only contemplating what he had said in silence. I did say I believe in reincarnation, but...

_...if it's true, then everything's made sense. Vast knowledge exceeding today's era, strange phrases he keep repeating everyday, everything is made sense now!_

"Why?" She blurted out. "Why do you tell me this, oyakata-sama?"

Nezuko didn't understand the purpose of him telling her this. Even if Tanjirou remembered his previous life vaguely, it didn't change that he was her one and only Big Brother.

She didn't care if her brother previously was someone evil or had caused misery. She didn't care if this life was his repent to his previous life.

Tanjirou is Tanjirou.

Ubuyashiki smiled as if he had heard her inner rant. "Because I believe that his first life--the previous life he had before this--will play a major part in the future," he sighed softly.

"What kind of part, I'm not entirely sure. Your brother is one of those unique being that can change the future at will.

But I trust you two. I know you two are good kids by heart. And perhaps, you will know what to do by holding that information."

His hand reached out and gave Nezuko a light pat, much to the young slayer's surprise.

"Be strong, Kamado Nezuko. You and your brother truly are blessed by Hino-kami."

_You two are loved._

So loved.

_(_ _Hino-kami_ _, or Fire God, could only refer to two Gods._

_One is _ _Kagutsuchi_ _, the God of Fire. His birth marks the end of the death and had caused destruction in early ages. Kagutsuchi was the patron deity of blacksmiths and ceramic workers._

_Yet, Kamado family weren't blacksmiths nor ceramic workers. They're coal burner, from ages to ages. It's didn't make any sense if they worship Kagutsuchi._

_And it only meant they worshipped the second deity:_

_Amaterasu__, the Goddess of Sun and Universe. The major deity of Shinto religion. The ruler of the sun and heaven. Her name deeply associated with other major deities, such as _ _Tsukuyomi_ _ and _ _Susanoo_ _._

_The fact that __Hinokami_ _Kagura_ _was made by several forms of Sun Breathing Techniques only escalated the fact._

_Kamado family are truly something, aren't they?)_

* * *

"Oh, come to think about it, Big Brother is really good at making stories."

Everyone looked at the only not-human person in the room. On that day, to lighten the mood after the last incident at swordsmith village, the pillars, together with some slayers they acquainted with, were having a massive dinner-slash-informal meeting. Nezuko was one of the invited guest.

Of course, Tanjirou was there too. Nezuko wouldn't ever dare to leave his brother alone.

(Not that he was uninvited. Everyone knew Nezuko always together with Tanjirou so inviting one of these sibling equals have those two as guests.)

Tanjirou, finally got back his ability to talk coherently, had a field day talking to Giyuu. The Water Pillar along the conversation only nodded back and spoke softly with a small smile(!) on his face. 

Some people didn't even try to hide their jealousy. They also wanted to talk with Tanjirou too.

The room was filled with chatters, loud munching, screaming, and sound of utensils clicking. Nezuko was too busy talking with Kanao she didn't realize the loud noises had started to quiet down and said those words.

"Making stories?" asked Kanao. Nezuko nodded.

"Since we had a four younger siblings, me and Big Brother always take turn babysitting them," the atmosphere went a little bit somber at the mention of their family. "When it come to make story time, Big Brother is the best"

Tanjirou's face went red at the non-stop praising. "Ne-Nezuko, you're exaggerating..."

"Umu, sounds interesting," Rengoku butted in with a big smile "I'd like to hear one of your story!"

"M-Me too!" Mitsuri raised her hand with blush on her cheek. Obanai growled jealously at the sight.

"Storytime from Tanjirou... Sounds good."

"G-Giyuu-san! Muchirou-kun!"

Soon, the others voiced their agreement much to Tanjirou's embarrassment. The pressure became doubled as Ubuyashiki said that he also curious about it.

"U-uuu..." Tanjirou sighed in defeat. "If Oyakata-sama insist, then I shall..." He then closed his eyes, eyebrows taunted as he tried to think what to tell.

_Oh my, how exciting!_ Nezuko clasped her hands in delight. She has been missing so bad Tanjirou's story time. It was one of most favorite thing they always do with their siblings.

_I wonder what will Big Brother tell us?_ The tale of female samurai who could travel between universe and world? The golden king and his clay friend? Or maybe, the tragic romance tale of female warrior and hero of nation!? _Ahhh, I can't wait!_

"--ah, that's it," Tanjirou opened his eyes and stars twinkled within. He deliberately coughed and shifted his sitting position. Everyone unconsciously relaxed their body.

_(For a moment, he looked so gentle and kind._

_It's heartwarming.)_

"It's a story of distant future," started Tanjirou. "A future where life can be modified by humans hand. A future where people playing Gods have become a norm.

A future where people have realized that they're no longer alone in this world."

No one spoke a word.

Tanjirou smiled with thousand meaning behind it and continued, "One day, a man who have conquered a battle of lifetime decided to counter-attack the doomed end. By using his connection, money, and his title as a survivor from the said battle, he build an organization. An organization whose purpose solely to preserve humanity and protect it from any anomaly that threatened its existence.

But that's not enough. They need someone. Someone who is kind and sincere at heart, yet in the same time untainted by the impurity of the world.

Yet, how? How can they find someone like that?"

"...They make them," Giyuu spoke softly. His face was still void from emotion, but his fist was shaking. "As 'playing God' has become a norm, it's not weird if they decided to 'make' them from scratch rather than finding the required people."

Tanjirou nodded solemnly. "You're right. Sensing it's no use to search people like that in this big world, they decided to make them from scratch.

A life that had golden heart and pure intention, yet not knowing about the world at all.

A gentle, lovely life that felt indebted with the humanity, simply because they are the one who created her. Because they allowed her to live, even though she can't give them anything. She believed to the deepest of her heart that was fated to fight since young, and died before her dream came true."

"But of course, that's not her ending," Tanjirou cocked his head in hidden amusement.

"Because--she hadn't met them yet. The one who will become her senpai, and later, the person she had vow to protect until she stopped breathing."

"...Too bad she can't meet them earlier. But before she had her fated meeting, a kind doctor offered a hand to her and..."

* * *

"-...and thus, that is the end of the tale of Mash Kyrlelight," Tanjirou clasped his hands once. "It's over. Ah, it's been a while since I tell someone a story... Sorry if it's a little bit boring--uh...

Everyone?"

No one answered. They were too busy crying rivers or tried to hold their tears but no avail.

_Why!?_

.

_(Years later, Nezuko realized it wasn't an ordinary story. Everything that he'd told her, was never ordinary._

_It's his fragments past.)_

* * *

"Nezuko."

"Yes, Big Brother?"

"...Can I accompany you to Demon Slayer training?"

"...Huh?"

* * *

"My, to think you're joining with us," Muzan tilted his head. "Tanjirou-kun."

The said demon growled to the walking abomination. Muzan only smiled amusedly.

"Still fighting me, I see. I can't understand why do you keep resisting me," said Muzan. He walked slowly approaching him. "Unlike those pathetic human you call as friends and sister, you're strong. So strong, that you resisted my own blood..."

He grabbed Tanjirou by neck and lifted him up. "So strong, that I really want to snap this thin neck of yours."

The younger man choked at the lack of breath. Muzan smiled at the sight.

"Let Big Brother go!" shouted Nezuko, shakily stood up from her place. Muzan threw her a glare.

"How annoying," Muzan murmured to himself. "I should have kill her sooner. Maybe then--"

"D-Don't..." Tanjirou growled in between his desperate grip. His red eyes burning in pure hate and detest. You... Dare...!"

"...Hou, so you want to play like that," Muzan's expression went neutral. His other free arm slowly raised until it's on the same level as Tanjirou's heart.

Nezuko's eyes went wide in fright and horror. _No no no no no don't you dare-_

"Then die."

There's a wet cracking sound and choked noise.

Her world went red and black.

"BIG BROTHER!"

* * *

.

.

_... It hurts._

_Am I... Dying?_

_Again, huh._

_\--wait_ _, again? Have I died back then?_

_...Oh--my previous life. Right._

_"...-g br-...-r! _ _D-_ _...!"_

_Who's that? ...Nezuko?_

_"_ _D-_ _..._ _mit_ _! I _ _c-_ _...!"_

_"_ _O-_ _....! _ _T-_ _..._ _rou_ _!"_

_"A-...!"_

_Oh, right... They are in the middle of battling Muzan, and I... am attacked by him._

_Dammit, me! Move! They're waiting for me! Open your eyes dammit don't you dare _ _die--_

_\--but_ _ I'm already...dying._

_Ah... How frustrating. Even though it's his second life, he has to die young like this. This is not good at all._

_...did my past self also died in young age? Then, sorry, Past Me. I can't protect your second life._

_Nezuko... Don't die, please. Everyone, please don't die. Please kill that _ _monster--please_ _ avenge those people who had been tormented by him!_

_"...!"_

_I'm sorry, I'm so sorry... I can't keep it anymore._

_So... Sleepy..._

_...ah... How sad, I don't even have enough time to remember my past life wholly. If only..._

_...i miss you, everyone... Mash, Dr. Roman, _ _Vinci-chan_ _..._

_..._

_..._

_Ser_ _..._

_..._ _vants_ _..._

_can...they?_

_...{Saber}..._

_..._

_..._

...

_ **{...Affirmative.}** _

_ **{Do not worry, my dearest Master. From now on I'll take over.}** _

_ **{Please. Sleep well.}** _

.

* * *

"How disappointing," Muzan tightened his grip on Nezuko's neck. Nezuko struggled hard. "You said you're going to kill me? Insolent human."

"I-I'll k-kill... You!" Nezuko hissed between her teeth with tears flowed nonstop. She couldn't think straight--her body and soul screamed grief and anger. She wanted to scream, to cry, to swing her blade until she couldn't feel her hands anymore.

Nezuko right now wanted nothing but blood of the man in front of him.

"I'll fucking kill you! You had killed my family, and now my brother! I'll kill you, Muzan! _I'll kill you **I'll kill you I'll**_\--"

"Enough," the young slayer let out a choked breath as the grip tightened. "This is getting nowhere."

"Nezuko-chan--!" Zenitsu called desperately. He tried to move his body but no avail. "D-damn it... M--move!"

Muzan laughed softly at the sight. "How pathetic, all of you," he said to the remaining slayers. Most had fainted and the others were barely had strength to fight. Muzan couldn't help but licked his lips.

He would have a feast tonight. And this girl, the one who had hindered his way to have Kamado Tanjirou as his, will be the main dish.

"I've told you before, little girl," Nezuko made a choked sound as his grip tightened. "You should've been not interfere with my doings and let me have you brother. Now he is dead and soon, you will."

Muzan chuckled at her despaired expression. Human, they're so easy to break and die. He didn't understand why they kept getting in his way to reach immortality.

_Ah, no use to think about it. They all will die in the end._

He didn't realize a shadowed figure approached soundlessly. They stopped behind him and grinned.

"Nope, I don't think I can let you do that."

Muzan instinctively kicked whoever at his back but didn't hit anything. He became alarmed and looked back.

"Who--Ghk!" Muzan clutched his slashed hand, releasing Nezuko from his deathly clutches. He glared at his attacker and growled his name like a curse.

"Kamado Tanjirou!"

"Eh?" Nezuko, barely took a breath and clutching her red throat, looked at her front. Her eyes went wide like saucer.

"Big Brothe--eh? Ehh?"

The remaining conscious demon slayer had the same incredulous expression.

No longer clad in demon slayer clothes, Tanjirou now was wearing a purple-red makeshift yukata with some decorations. There was a high-quality katana rest on his right hand while other three hanged on his hips.

But the most striking was his eyes. His usual burgundy eyes now a mix between blue and gray--like a clouded sky, brimming with pride and confidence.

Was he really Tanjirou?

"Ahhh, I see. So his name now is Kamado Tanjirou, huh?" The man nodded to himself with satisfied smile. "Hahaha, not bad, not bad! You're truly always amuse me!"

Nezuko walked slowly at the cheery(?) man. "You're... Big Brother?"

not-Tanjirou make a surprised face with red hue(?) spreading on cheek. "Oh my, what a cute girl you are!" He cooed, much to her shock. "You're his younger sister, aren't you? So cute!"

"Um," Nezuko shifted uncomfortably.

"--ah, sorry!" He laughed awkwardly. "To answer your question, I'm still your brother! Well, at least this body and the soul that currently resting inside. I'm just borrowing his body--don't worry, it's all consent!"

"B-Borrowing?"

"Umu," not-Tanjirou unsheathed his(_is the spirit inside Tanjirou was male? Or female?_) other sword on left hand.

"For now, call me Saber a'ight?"

* * *

Saber is strong.

It was not a praise; it's a statement.

He--she?--they didn't use nichirin blade, which was weird, yet--

Another leg chopped and shredded into million pieces. Muzan howled in pain.

They could hurt him. Their blade might not a nichirin but it had strange ability that able to cut demon's flesh.

But, the blade wasn't the main reason. It was their skill. Their skill--

"_Hail the __Tenmandaijizaitenjin__,_

_Sever the spirit in the sword!"_

\--their skill couldn't be described except _divine_. Whenever they swing their swords, something broke and crumbled. Any attack quickly depleted and dodged even if they didn't see where it came. As if he had another eyes at his back.

As if their blade couldn't miss. Any attack was simply inevitable to avoid.

They are [human]. How they carried themselves was the proof. They were not something as twisted like Muzan, yet they were able to stand on the same ground as the self-proclaimed God.

_"Exterminate every kind of evil with rage,_

_Hayagriva_ _!"_

(As he swung his sword, everything become nothing. Not more, not less.

Void.)

"_This single stroke is surely my path of the void, my way of life!_"

(His sword was the epitome of nothingness.

Muzan didn't stand a chance. He never did.)

"_Īśāna__ great manifestation!"_

* * *

It was an exhausting battle. Many young lives were taken by demons, but justice was rightfully served.

Muzan is no more.

Approximately, they needed two months to at least recover enough to do mundane things. It's pure a miracle that most of pillars, except Kochou and Muichirou who sadly didn't survive the battle, survived the fortress.

It all thanks to that person who had 'borrowing' Tanjirou's body.

The said man, however, fainted as the last piece of what remains of Muzan had crumbled into nothing. He hadn't been wake up ever since.

Nezuko was worried sick with her brother's condition. Was he alright? How could she give him the medicine if he's in comatose? What if he won't wake up forever?

What if this 'Saber' man takeover Tanjirou's body forever?

\--no. She must not give up. She must believed Tanjirou would wake up as his true self. Then, she would give him the cure so he could turn back into a human.

That's the only reason why she had been fighting all the time. The reason why she became a demon slayer.

If--if Tanjirou in the end had the same fate as her family--

Nezuko shook her head didn't dare to finish the thought. _No__, no, no. Bad Nezuko. Stop the dark thoughts. Big Brother won't like it._

The young demon slayer stared forlornly at the sleeping figure on bed. The white sheet made Tanjirou seemed smaller.

_He looks so calm,_ she thought, caressing his temple. _Do you have a good dream,_ _Big Brother?_ _Like I have in infinity train?_

_Or do you dream about your previous life? The reason why that Saber guy can take over your body?_

Nezuko had connected all the dots. The way Saber treated Tanjirou's name as if it was his second name and how they tried their best to avoid getting external wound only meant that Saber had some connection to Tanjirou's past life.

She remembered the small message they gave to her. A short sentence, full of fondness with a tint of sadness.

_"He's so lucky to have someone like you as your sister. I'm glad."_

Nezuko knew Tanjirou is a God-send. She knew very well how lucky she was, having someone so amazing like Tanjirou as her big brother.

But, for someone she barely knew say that Tanjirou is so lucky to have a sister like her...

Someone who might or might not knew his past self very well...

She didn't know what to say.

"...Say, Big Brother," Nezuko held Tanjirou gently. It felt warm.

"Are you afraid that I won't accept you anymore? Is that why you haven't wake up until now?"

Silence. There's no answer.

It didn't matter.

"You're wrong, Big Brother. I do not care who you were and what had you done in past life. Big Brother is Big Brother--the eldest and first son of Kamado family, my one and only Big Brother."

_(She didn't realize the small presences behind door. The young girls of Butterfly Estate quietly placed _ _'do_ _ not _ _enter'_ _ notice and leave. They could visit Tanjirou later._

_Giving the Kamado siblings a personal space was the least thing they could do for their idol.)_

"I don't think others will turn their back on you, Big Brother. You're so loved and they crave for your love too. Yesterday, Zenitsu-kun snooped some sweet buns but he got caught. Inosuke made calligraphy of your name--it's messy, but I bet you'll be surprised. He wrote it in kanji! Ah, Shinazugawa-san promised to buy you ohagi when you wake up--a payment for saving Genya, he said. Can't say I trust him though. I also found a stack of letters from Giyuu-san to you--no wonder he never replied back, his crow is very old and forgetful! Rengoku-san and Senjurou-kun sometimes visit you too. Poor Senjurou, he cried his eyes out the first time he saw you. I can't read Rengoku-san's expression, but he radiated scary aura. I guess he's very angry. Surprisingly, Kanroji-san and Iguro-san send you 'get well soon' gift. You should check it out, it's screamed very Kanroji-san! Also..."

Nezuko kept ranting and ranting about anything inside her head. She talked about demon slayer, about their young superior, about what she had ate, about today's weather, about the dress she saw before, and so on.

She talked and talked until her throat felt painful, but,

It's not enough.

It is not enough.

"I admit, this past month is truly the calmest moment I've ever felt after become a demon slayer," she confessed. "But it's not enough."

A pause.

"I can't enjoy it if you're still sleeping like this, Big Brother. It's not fair. We can have this peace all thanks to you but--if you can't enjoy it at all, isn't that just cruel? That's why, please,"

_(She wouldn't know what to do if she lost her only family left.)_

"Wake up, Onii-chan."

_(Tanjirou is Nezuko's home.)_

"I miss you."

_(Losing him means she lost her home. Forever.)_

* * *

"Still hasn't waken up?"

Nezuko nodded to Giyuu with a weak smile. It had been three months after the last battle with Muzan. After that, their jobs had became much calmer--giving antidotes to demons or killing them off who beyond saved.

The demon slayer corps had finally done their job and soon it will be be dissolved. Some planned to go back to their previous life, some made a plan for future business, or simply would continue working under young Ubuyashiki family head.

Nezuko honestly didn't know what to do. Many people had offered her to join their business, or even asked her and her brother to join their family a.k.a. adoption.

But at this time she felt she wasn't ready for it. Not when Tanjirou still refused to open his eyes.

"There's some black strokes on his hair," commented Giyuu, pointing at discolored streaks on Tanjirou's head. "Is this the side effect of the medicine?"

A couple weeks ago, they decided to give the antidote to Tanjirou via needle. It's because he was physically ready, it's just his consciousness that didn't come back no matter what they did.

So far Tanjirou didn't show any discomfort, only black streaks that appeared on his hair. But, was it truly the side effect of the medicine?

"Maybe," answered Nezuko. "I don't know very well."

Giyuu nodded and stood beside where Nezuko sat, stared at the sleeping figure with thousands feeling glistened on his dark blue eyes.

"...I hope he wake up soon."

Nezuko nodded. "Yeah. There's a lot I want to say to Big Brother."

Wait and hope, Tanjirou once said. Nezuko decided to hold on it.

Wait and hope.

* * *

It happened exactly four years years after Muzan killed her family.

At that time, Nezuko was in another room, teaching the young girls in Butterfly Estate basic math. Suddenly Matsuemon, her crow, barged in with flustered feathers and screamed,

"CAWWW! KAMADO TANJIROU HAS WAKEN UP! I REPEAT, KAMADO TANJIROU HAS WAKEN UP!"

Nezuko had already left once his name was mentioned. She ran as fast as she could, to the point using Thunder Breath to speed up.

_Tanjirou,_ was only in her mind. _Tanjirou has waken up._

_Tanjirou._

_Tanjirou._

_Tanjirou._

_Tanjirou--out_ _ of my way, you damn door!_

"NII-CHAN!"

"AAAAAH!" Tanjirou screamed as the wooden door flied away to the other side of the room. "God, Nezuko, you don't have to kick the door. Aoi-chan will scold you aga--ompf!"

Tanjirou didn't have a chance to finish his words as Nezuko engulfed him into a hug. He went quiet when her shoulder shook and there was wet spot growing on his shirt.

"Nezu...ko?"

"Shut up," sobbed Nezuko and tighten her hug. "Three months, two weeks, and five days. You've been out for that long, Big Brother."

"...ah," was his respond. He then replied her hug with his own. Nezuko sobbed harder. "I'm sorry for leaving you alone, Nezuko."

"_Sniff_\--damn yes you are! You--you're not allowed to-to sleep that long again!"

"Yes, yes. I promise, Nezuko. I promise."

They stayed on that position for a while until Nezuko patted his shoulder. "It's okay now," she whispered and untangle her hug. "Everyone's waiting for you, Big Brother."

Tanjirou took a sniff and smiled as his nose caught familiar smells. "They're outside," he said.

"I know."

After wiped her tears away, Nezuko finally could take a good look at his now cured big brother. She gasped as something had changed on his face.

"B-Big Brother..." she stuttered. "Your left eye--?"

"...what happened to my left eye?"

Nezuko paused, didn't immediately answered away.

She was too entranced by its beauty.

His left eye now had the same shade as clear sky blue mixed with starry night sky. When she stared on it, Nezuko felt like she was embraced into comforting warmth and sunshine.

(Yes, it's her brother alright. No one able to made someone felt so safe just by gazed at his eyes.)

Even if it had changed color, the kindness was unchanged. Rather it enhanced Tanjirou's look as if he wasn't already beautiful enough.

"It's blue, like sky in the morning," Tanjirou paused at her word. "Mixed with night sky. Like Giyuu-san's but softer."

"I see..." Tanjirou went silent for a moment.

"Do you hate it? Do you think it's creepy?"

Nezuko didn't have to think. "No," she said. "It isn't creepy at all. In fact, I love it! It looks so pretty and it pairs so well with your burgundy eye! It's not weird at all!"

Tanjirou blushed at her compliment but kept pushing. "You sure?" he said. His arms moved like he wanted to say something but didn't know how. "Even if it's..."

"It's?"

"..." Tanjirou stared straight to Nezuko as if he was reading her mind. She didn't say anything, only steadied her eyes to met his mismatched one.

Deep red met burgundy and blue sky.

"...It seems I'm the wrong here," Tanjirou broke their stare contest by let out a big sigh and smiled to himself. "Sorry Nezuko. Your Big Brother has become rather foolish after sleeping too much."

Nezuko tilted her head in confusion. "What do you mean?"

"No, nothing. I'm just--"

"Ooooooiiii! Zukonabuko! Gonpakachiroto! Until when I must wait you two being fuwafuwa?!"

The two sibling jumped in surprise as Inosuke barged in loudly, which followed by everyone. "I can't wait anymore! Oi, Gonpakachiroto, why the heck must you sleeping that long? Can't you see I'm tired waiting?"

"Inosuke, that's not even resembling Big Brother's name! And who the heck is Zukonabuko?"

"TANJIROOOOOOO--WAIT WHAT THE HECK HAPPENED TO YOUR LEFT EYEEE-"

"Young Tanjirou, I'm glad you're fine! Umu, your left eye looks good too!"

"My, isn't it look good on you!

"Tch. Why it must similar with that damn Tamioka?"

"Tanjirou-kun, finally you're awake!"

"...It's blue."

"Tanjirou!"

"Kamado!"

"Tanjirou-kun!"

Nezuko watched the commotion with a happy smile.

_See, Big Brother? You're loved here._

She had a gist about what's in Tanjirou's head before. He was talking about how his past self influenced his present self, and causing those minor changes on his body.

She didn't mind it. Tanjirou is Tanjirou.

She didn't care about his past. She didn't care if he was a demon, animal, or even alien. She didn't even care if he was evil person like Muzan, or beautiful one like Ubuyashiki Kagaya.

_What's important now is the present and future._

But... She won't mind if one day Tanjirou decided to share his past with her. At very least, she wanted to know this Saber guy who had 'borrowed' his body.

**Author's Note:**

> i thank thee for read this fic until the very last part  
idk how to end it tho


End file.
